package com.bdqn.Di1Zhan;


import org.apache.log4j.Logger;

import javax.servlet.http.HttpServletRequest;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Map;

public class SimpleBeanConvertor {
    private static Logger log = Logger.getLogger(SimpleBeanConvertor.class);

    public static <T> T convert(HttpServletRequest request , Class<T> targetType)
        throws IllegalAccessException , InstantiationException , ParseException ,UnsupportedTypeException , InvocationTargetException{
        Map<String , String[]>params = request.getParameterMap();
        if (params.size() == 0)return null;

        T target = targetType.newInstance();

        Method[] allMethods = targetType.getMethods();

        if (allMethods != null && allMethods.length > 0){
            for (Method method:allMethods) {
                if (method.getName().startsWith("set")){
                    Class[] args = method.getParameterTypes();
                    if (args.length == 1){
                        String paramName = method.getName().substring(3,4).toLowerCase() + method.getName().substring(4);
                        if (params.containsKey(paramName)){
                            try {
                                Object value = parsetValue(params.get(paramName) , args[0]);

                                method.invoke(target , value);
                            }catch (ParseException e){
                                log.debug("参数转换错误",e);
                                e.printStackTrace();
                                throw e;
                            }
                        }else if (Boolean.class == args[0] || boolean.class == args[0]){
                            method.invoke(target , false);
                        }
                    }
                }
            }
        }
        return target;
    }

    private static Object parsetValue(String[] value , Class type) throws ParseException , UnsupportedTypeException{
        if (String.class == type)
            return value[0];
        if (java.util.Date.class == type)
            return new SimpleDateFormat("yyyy-MM-dd").parse(value[0]);
        if (boolean.class == type || Boolean.class == type)
            return true;
        if (char.class == type || Character.class == type)
            return value[0].charAt(0);
        if (int.class == type || Integer.class == type)
            return Integer.valueOf(value[0]);
        if (short.class == type || byte.class == type || long.class == type || float.class == type || double.class == type)
            try {
                type = Class.forName("java.lang."+type.getName().substring(0,1).toUpperCase()+type.getName().substring(1));
            }catch (ClassNotFoundException e){
                e.printStackTrace();
            }
        if (type.getName().startsWith("java.lang.") || type.getName().startsWith("java.math."))
            try {
                return type.getConstructor(String.class).newInstance(value[0]);
            }catch (Exception e){
                throw new UnsupportedTypeException(e);
            }
        throw new UnsupportedTypeException();
    }
}
